Semiconductor memories are used for storage of information. Various types of memories are available. One type of memories is non-volatile memories (NVMs). Non-volatile memories maintain information stored, even when power is turned off. Non-volatile memories may be employed as stand-alone devices, such as NVM devices. Non-volatile memories may also be integrated with other circuit modules, such as in the case of a system-on-chip (SoC) device. For example, a SOC may include logic and processing memory modules integrated into an integrated circuit (IC) or chip.
Non-volatile memories include associated circuitry for accessing memory cells. One circuit needed is a charge pump. The charge pump is a high voltage (HV) charge pump which generates a high voltage used in program or erase memory accesses of the NVM cells. An integral component of a charge pump is the capacitor. A charge pump includes a plurality of high capacitance capacitors for generating a high voltage output, which can be multiple times that of the input voltage.
However, conventional capacitors employed in charge pumps occupy large areas. For example, capacitance is related to the area of the capacitor. This can result in the capacitors occupying a significant part of the overall area of the charge pump. For example, the capacitors may occupy about 95% of the total area of the charge pump.
From the foregoing discussion, it is desirable to provide a capacitor which has a high capacitance per area ratio, enabling reduction of area occupied, for example, for charge pumps.